Dell XPS 15 and Linux - a developer’s dream

September 16th, 2016

This is one of the few and longer review articles I write on this site, for two reasons. First of all I am pretty dissatisfied with Apple’s laptops (and workstations) for a decade, and second Dell provided me with XPS 15 to try for a few weeks.

Read the rest of this entry »

Screen on a serial port

September 16th, 2016

Although I use and develop on Linux for a very, very, very long time it never had the idea to use screen as a terminal emulator on a serial port for an embedded board.

Turs out that is very well support and just works:

screen /dev/ttyUSB0 115200

Innovation under Tim Cook

September 2nd, 2016

Meanwhile at Apple HQ:

Tim: Hm, our year over year sales are down, again. How can we innovate to get this up again?

… hm, head-scratch, nose poke, silence in the audience, …

Tim: ok lets also take away the headphone jack so at least every iPhone user also needs to get a new one and third party companies pay us more Lightning port chip royalties.

Not really what we ask for in regards to better battery life or updates Mac line, … not to say the display word, …

Welcome to the brave new Apple, … run by bean counters, … :-/

Getting tired of permanent MacBook battery failure

August 26th, 2016

So this stupidly smart Apple MacBook batteries set a permanent failure bit once they are simply discharged by sitting on a shelf for a month or two. With this permanent failure bit the controller will not charge them again, even when the cells are brand new and otherwise perfectly fine. Another day I need to try sending a reset sequence or otherwise rewriting some flash cells, sigh:


Some notes for now:

Battery Firmware Hacking

MacBook battery (Rom) cycle reset

15″ Retina MacBook Pro Late 2013 vs. Dell XPS

August 2nd, 2016

People who know me certainly know by now how disappointed and frustrated I became over the last years with Apple’s MacBook lineup and their hardware refresh. Or better, the lack of it, …

The other month Dell was so kind to send a Dell XPS 15 to me to give it a try. While I’m still writing on a full review I wanted to share a first performance figure compiling the Linux 4.7 kernel from an external USB3 SSD, both with 16GB RAM.

rMacBookPro late-2013 w/ i7-4850HQ CPU @ 2.30GHz: 20m48s, 145m40s
Dell XPS 15 w/  i7-6700HQ CPU @ 2.60GHz: 13m32s, 92m14s

The first time is total wall clock time, the second is total CPU time due parallelism as shown by time(2).

Yep, that is some whooping 35% faster

And a contributing factor for Apple’s MacBook loosing so much is also the notoriously underdesigned thermal system, fans, and heatsink and such. As the Linux kernel points out quite some thermal throttling on the Apple machine, but not on the Dell:


CPU5: Core temperature above threshold, cpu clock throttled (total events = 1)
CPU1: Core temperature above threshold, cpu clock throttled (total events = 1)
CPU3: Package temperature above threshold, cpu clock throttled (total events = 1)
CPU2: Package temperature above threshold, cpu clock throttled (total events = 1)
CPU4: Package temperature above threshold, cpu clock throttled (total events = 1)
CPU6: Package temperature above threshold, cpu clock throttled (total events = 1)
CPU7: Package temperature above threshold, cpu clock throttled (total events = 1)
CPU0: Package temperature above threshold, cpu clock throttled (total events = 1)
CPU1: Package temperature above threshold, cpu clock throttled (total events = 1)
mce: [Hardware Error]: Machine check events logged
CPU5: Package temperature above threshold, cpu clock throttled (total events = 1)
mce: [Hardware Error]: Machine check events logged

Amazon BuyVIP

July 20th, 2016

Recently Amazon started to spam my email account regarding their http://de.buyvip.com rebranding / “microsite”. I really wonder about Amazon’s benefits in this case, why not simply run this from their main site, … Lure those people back who are not satisfied with the Amazon experience by using another brand? Or some special mass promotion sales contracts?

The sad state of silicon

April 26th, 2016

So I wanted to do some Qemu/KVM tests. Turns out all my aging local AMD boards have not yet an IOMMU in the chipset, sigh (though it sounds like the AMD Phenom II cpus would otherwise include one already?).

I wish I could already buy some AMD Zen silicon - just to support them, you know, …

So I looked at Intel for some single socket heavy multi core CPU.

Turns out their situation around Xeon CPUs is totally ridiculous. If you want more than a couple of cores you are left with 3++ years old silicon, look here:
Xeon e3 v5 (Skylake) about up to 8 cores

Xeon e3 v4 (Broadwell) somehow also only up to 8 cores
Only Xeon e3 v3 (Haswell) exist the heavy up to 18 !!!! cores per modul, beasts … :-/
ok, that thing is some 6000 EUR, maybe I do not really want that ;-)
18 cores, 36 threads
and right now at Xeon v5 just 4 cores, 8 threads???
Everyone is talking about how little AMD is delivering - but seriously, what crazy outdated silicon is that at Intel?

If I am going to spent some 1000++ EUR for a CPU, I will definitely not award it toward a 3++ years old chip architecture, … :-/

Mac OS X Disable System Integrity Protection

April 12th, 2016

As Mac OS X requires booting the recovery partition to disable SIP. What does the command:

csrutil disabled

actually do?

Looks like it sets

csr-active-config w%00%00%00

in the nvram.

Religionsschlüsselverzeichnis

January 18th, 2016

In 2015 wurde das Meldeverfahren für Kapitalerträge für Kirchensteuern geändert, und dabei neue, komplizierte, und nicht oft publizierte Religionsschlüssel eingeführt. Schulder müssen sich jetzt theoretisch beim Bundeszentralamt für Steuern für die Abfrage dieser Schlüssel schriftlich anmelden, und dann jährlich den Religionsschlüssel elektronisch abfragen (WTF?). Da man diese im Internet nicht oft findet hier eine kurze Textaufstellung. Da nicht von mir erdacht und nur von Staatsquellen übernommen keine Gewähr auf Richtigkeit oder Vollständigkeit:

010600 Evangelische Landeskirche Anhalts
010100 Evangelische Landeskirche in Baden
010200 Evangelisch-Lutherische Kirche in Bayern
010300 Evangelische Kirche Berlin-Brandenburg-schlesische Oberlausitz
010400 Evangelisch-lutherische Landeskirche in Braunschweig
010500 Bremische Evangelische Kirche
010800 Evangelisch-lutherische Landeskirche Hannovers
010900 Evangelische Kirche in Hessen und Nassau
011000 Evangelische Kirche von Kurhessen-Waldeck
011100 Lippische Landeskirche
012400 Evangelische Kirche in Mitteldeutschland
011200 Evangelisch-Lutherische Kirche in Norddeutschland
011300 Evangelisch-Lutherische Kirche in Oldenburg
011600 Evangelische Kirche der Pfalz
011400 Evangelisch-reformierte Kirche
011500 Evangelische Kirche im Rheinland
012300 Evangelisch-Lutherische Landeskirche Sachsens
011700 Evangelisch-Lutherische Landeskirche Schaumburg-Lippe
011900 Evangelische Kirche von Westfalen
012000 Evangelische Landeskirche in Württemberg
025100 Bistum Aachen
025200 Bistum Augsburg
025300 Erzbistum Bamberg
025400 Erzbistum Berlin
025500 Bistum Dresden-Meißen
025600 Bistum Eichstätt
025700 Bistum Erfurt
025800 Bistum Essen
025900 Erzbistum Freiburg
026000 Bistum Fulda
026100 Bistum Görlitz
027400 Erzbistum Hamburg
026200 Bistum Hildesheim
026300 Erzbistum Köln.
026400 Bistum Limburg
026500 Bistum Magdeburg
026600 Bistum Mainz
026700 Erzbistum München und Freising
026800 Bistum Münster (Nordrhein-westfälischer Teil)
026900 Bistum Osnabrück
027000 Erzbistum Paderborn
027100 Bistum Passau
027200 Bistum Regensburg
027300 Bistum Rottenburg-Stuttgart
027500 Bistum Speyer
027600 Bistum Trier
027700 Bistum Würzburg
027800 Offizialatsbezirk Oldenburg (Bistum Münster)
033200 Katholisches Bistum der Alt-Katholiken in Deutschland
044000 Israelitische Religionsgemeinschaft Baden
044100 Israelitische Religionsgemeinschaft Württembergs
044200 Landesverband der Israelitischen Kultusgemeinden in Bayern
044300 Jüdische Gemeinde in Hamburg
044400 Jüdische Gemeinde Frankfurt am Main
044500 Kultussteuerberechtigte jüdische Gemeinden im Landesverband Hessen
044600 Landesverband der Jüdischen Gemeinden von Nordrhein, Landesverband der Jüdischen Gemeinden von Westfalen- Lippe und Synagogen-Gemeinde Köln
044700 Jüdische Kultusgemeinde Bad Kreuznach
044800 Jüdische Kultusgemeinde Koblenz
044900 Synagogengemeinde Saar
058200 Freireligiöse Landesgemeinde Baden
058300 Freireligiöse Gemeinde Offenbach
058400 Freireligiöse Landesgemeinde Pfalz
058500 Freireligiöse Gemeinde Mainz
058600 Freie Religionsgemeinschaft Alzey

BootCamp driver download

January 10th, 2016

So Apple does not publish nice Windows driver downloads, you need the BootCamp.app for that, sigh. You need to download hundreds of megabytes even if you only need a driver, or two, sigh.

And where does it store it? /Library/Application\ Support/BootCamp/